Pretty sure this has been done recently, but the only threads I can find on 'Search' are from 2008, so not particularly helpful... 
Planning a trip with the family to Paris in August and wondering what happens on the Metro. I've heard about the Navigo app thing, but how does that work with a family - we all have to have the app?
I assume you can still go and buy the tickets from the machines, would that be easier for us? Is there a family ticket thing? There's two adults and a 15 year old going.
Any help would be great (plus any tips on good things to do in Paris over 5 days). Thanks ever so.